Abstract

The U.S. population is plagued by physical inactivity, lack of cardiorespiratory fitness, and sedentary lifestyles, all of which are strongly associated with the emerging epidemic of chronic disease. The time is right to incorporate physical activity assessment and promotion into health care in a manner that engages clinicians and patients. In April 2015, the American College of Sports Medicine and Kaiser Permanente convened a joint consensus meeting of subject matter experts from stakeholder organizations to discuss the development and implementation of a physical activity vital sign (PAVS) to be obtained and recorded at every medical visit for every patient. This statement represents a summary of the discussion, recommendations, and next steps developed during the consensus meeting. Foremost, it is a "call to action" for current and future clinicians and the health care community to implement a PAVS in daily practice with every patient.

Abstract

While the preparticipation evaluation (PPE) is widely used by medical practitioners, its overall effectiveness is unknown, in part because there are no standardized or centralized mechanisms to collect and analyze medical history information.To report on the injuries and illnesses identified with the use of an electronic PPE (ePPE) completed by first-time National Collegiate Athletic Association Division 1 varsity sport participants (N = 1693; 797 women, 896 men) upon entry to a single institution between 2010 and 2013.Cross-sectional study; Level of evidence, 3.In total, 3126 discrete past injuries were reported (women, 1473 injuries; men, 1653 injuries). Time loss from sport participation averaged 31.4 days for each injury (women, 32.2 days; men, 30.7 days), and aggregate time loss from sport for all student-athletes before the ePPE was 256 years. Eleven percent of student-athletes had injuries that were unresolved and still symptomatic at the time of the ePPE. Thirty percent of injured student-athletes had a history of ≥1 surgeries for an injury (women, 176; men, 213), and these accounted for 57% of the time lost from sport before college participation. Head injuries accounted for 9% (110 women, 173 men), and loss of consciousness was reported in 19% of these. One in 3 student-athletes answered "yes" to ≥1 of the American Heart Association questions on cardiovascular health. While 15% of women reported a history of stress fracture, only 3% reported a diagnosed eating disorder.While some data in this population are self-evident, we were not aware of the high frequency of past injuries, the magnitude of time lost from sport, the high frequency of past surgery, and the number of participants still symptomatic from injuries. The ePPE is a valuable tool for collecting and analyzing aggregate injury and illness data in athletes, such as the finding that 11% of injuries that were reported were unresolved and still symptomatic.

Abstract

Bridging the knowing-doing gap in the prevention of chronic disease requires deep appreciation and understanding of the complexities inherent in behavioral change. Strategies that have relied exclusively on the implementation of evidence-based data have not yielded the desired progress. The tools of human-centered design, used in conjunction with evidence-based data, hold much promise in providing an optimal approach for advancing disease prevention efforts. Directing the focus toward wide-scale education and application of human-centered design techniques among healthcare professionals will rapidly multiply their effective ability to bring the kind of substantial results in disease prevention that have eluded the healthcare industry for decades. This, in turn, would increase the likelihood of prevention by design.

Abstract

The purpose of this study was to validate a recently proposed return-to-play (RTP) decision model that simplifies the complex process into three underlying constructs: injury type and severity, sport injury risk, and factors unrelated to injury risk (decision modifiers). We used a cross-over design and provided clinical vignettes to clinicians involved in RTP decision making through an online survey. Each vignette included examples changing injury severity, sport risk (e.g. different positions), and non-injury risk factors (e.g. financial considerations). As the three-step model suggests, clinicians increased restrictions as injury severity increased, and also changed RTP decisions when factors related to sport risk and factors unrelated to sport risk were changed. The effect was different for different injury severities and clinical cases, suggesting context dependency. The model was also consistent with recommendations made by subgroups of clinicians: sport medicine physicians, non-sport medicine physicians, and allied health care workers.

Abstract

Repeated-measures clinical measurement reliability study.To establish the reliability and face validity of the Functional Lower Extremity Evaluation (FLEE).The FLEE is a 45-minute battery of 8 standardized functional performance tests that measures 3 components of lower extremity function: control, power, and endurance. The reliability and normative values for the FLEE in healthy athletes are unknown.A face validity survey for the FLEE was sent to sports medicine personnel to evaluate the level of importance and frequency of clinical usage of each test included in the FLEE. The FLEE was then administered and rated for 40 uninjured athletes. To assess test-retest reliability, each athlete was tested twice, 1 week apart, by the same rater. To assess interrater reliability, 3 raters scored each athlete during 1 of the testing sessions. Intraclass correlation coefficients were used to assess the test-retest and interrater reliability of each of the FLEE tests.In the face validity survey, the FLEE tests were rated as highly important by 58% to 71% of respondents but frequently used by only 26% to 45% of respondents. Interrater reliability intraclass correlation coefficients ranged from 0.83 to 1.00, and test-retest reliability ranged from 0.71 to 0.95.The FLEE tests are considered clinically important for assessing lower extremity function by sports medicine personnel but are underused. The FLEE also is a reliable assessment tool. Future studies are required to determine if use of the FLEE to make return-to-play decisions may reduce reinjury rates.

Abstract

The female athlete triad is a medical condition often observed in physically active girls and women and involves three components: (1) low energy availability with or without disordered eating, (2) menstrual dysfunction, and (3) low bone mineral density. Female athletes often present with one or more of the three triad components, and early intervention is essential to prevent its progression to serious end points that include clinical eating disorders, amenorrhea, and osteoporosis. This consensus statement presents a set of recommendations developed following the first (San Francisco, CA) and second (Indianapolis, IN) International Symposia on the Female Athlete Triad. This consensus statement was intended to provide clinical guidelines for physicians, athletic trainers, and other health care providers for the screening, diagnosis, and treatment of the female athlete triad and to provide clear recommendations for return to play. The expert panel has proposed a risk stratification point system that takes into account magnitude of risk to assist the physician in decision making regarding sport participation, clearance, and return to play. Guidelines are offered for clearance categories, management by a multidisciplinary team, and implementation of treatment contracts.

Abstract

To describe the variability in the return-to-play (RTP) decisions of experienced team clinicians and to assess their clinical opinion as to the relevance of 19 factors described in a RTP decision-making model.Survey questionnaire.Advanced Team Physician Course.Sixty seven of 101 sports medicine clinicians completed the questionnaire.Results were analyzed using descriptive statistics. For categorical variables, we report percentage and frequency. For continuous variables, we report mean (SD) if data were approximately normally distributed and frequencies for clinically relevant categories for skewed data.The average number of years of clinical sports medicine experience was 13.6 (9.8). Of the 62 clinicians who responded fully, 35% (n = 22) would "clear" (vs "not clear") an athlete to participate in sport even if the risk of an acute reinjury or long-term sequelae is increased. When respondents were given 6 different RTP options rather than binary choices, there were increased discrepancies across some injury risk scenarios. For example, 8.1% to 16.1% of respondents who chose to clear an athlete when presented with binary choices, later chose to "not clear" an athlete when given 6 graded RTP options. The respondents often considered factors of potential importance to athletes as nonimportant to the RTP decision process if risk of reinjury was unaffected (range, n = 4 [10%] to n = 19 [45%]).There is a high degree of variability in how different clinicians weight the different factors related to RTP decision making. More precise definitions decrease but do not eliminate this variability.

Abstract

Morbidity and mortality from preventable, non-communicable chronic disease (NCD) threatens the health of our populations and our economies. The accumulation of vast amounts of scientific knowledge has done little to change this. New and innovative thinking is essential to foster new creative approaches that leverage and integrate evidence through the support of big data, technology, and design thinking. The purpose of this paper is to summarize the results of a consensus meeting on NCD prevention sponsored by the International Olympic Committee (IOC) in April, 2013. Within the context of advocacy for multifaceted systems change, the IOC's focus is to create solutions that gain traction within health care systems. The group of participants attending the meeting achieved consensus on a strategy for the prevention and management of chronic disease that includes the following: 1. Focus on behavioural change as the core component of all clinical programs for the prevention and management of chronic disease. 2. Establish actual centres to design, implement, study, and improve preventive programs for chronic disease. 3. Use human-centered design in the creation of prevention programs with an inclination to action, rapid prototyping and multiple iterations. 4. Extend the knowledge and skills of Sports and Exercise Medicine (SEM) professionals to build new programs for the prevention and treatment of chronic disease focused on physical activity, diet and lifestyle. 5. Mobilize resources and leverage networks to scale and distribute programs of prevention. True innovation lies in the ability to align thinking around these core strategies to ensure successful implementation of NCD prevention and management programs within health care. The IOC and SEM community are in an ideal position to lead this disruptive change. The outcome of the consensus meeting was the creation of the IOC Non-Communicable Diseases ad-hoc Working Group charged with the responsibility of moving this agenda forward.

Abstract

Morbidity and mortality from preventable, non-communicable chronic disease (NCD) threatens the health of our populations and our economies. The accumulation of vast amounts of scientific knowledge has done little to change this. New and innovative thinking is essential to foster new creative approaches that leverage and integrate evidence through the support of big data, technology and design thinking. The purpose of this paper is to summarise the results of a consensus meeting on NCD prevention sponsored by the IOC in April 2013. Within the context of advocacy for multifaceted systems change, the IOC's focus is to create solutions that gain traction within healthcare systems. The group of participants attending the meeting achieved consensus on a strategy for the prevention and management of chronic disease that includes the following: (1) Focus on behavioural change as the core component of all clinical programmes for the prevention and management of chronic disease. (2) Establish actual centres to design, implement, study and improve preventive programmes for chronic disease. (3) Use human-centred design in the creation of prevention programmes with an inclination to action, rapid prototyping and multiple iterations. (4) Extend the knowledge and skills of Sports and Exercise Medicine (SEM) professionals to build new programmes for the prevention and treatment of chronic disease focused on physical activity, diet and lifestyle. (5) Mobilise resources and leverage networks to scale and distribute programmes of prevention. True innovation lies in the ability to align thinking around these core strategies to ensure successful implementation of NCD prevention and management programmes within healthcare. The IOC and SEM community are in an ideal position to lead this disruptive change. The outcome of the consensus meeting was the creation of the IOC Non-Communicable Diseases ad hoc Working Group charged with the responsibility of moving this agenda forward.

Abstract

Context: The Functional Movement Screen (FMS) is a popular test to evaluate the degree of painful, dysfunctional, and asymmetric movement patterns. Despite great interest in the FMS, test-retest reliability data have not been published. Objective: To assess the test-retest and interrater reliability of the FMS and to compare the scoring by 1 rater during a live session and the same session on video. Design: Cross-sectional study. Setting: Human performance laboratory in the sports medicine center. Patients or Other Participants: A total of 21 female (age = 19.6 ± 1.5 years, height = 1.7 ± 0.1 m, mass = 64.4 ± 5.1 kg) and 18 male (age = 19.7 ± 1.0 years, height = 1.9 ± 0.1 m, mass = 80.1 ± 9.9 kg) National Collegiate Athletic Association Division IA varsity athletes volunteered. Intervention(s): Each athlete was tested and retested 1 week later by the same rater who also scored the athlete's first session from a video recording. Five other raters scored the video from the first session. Main Outcome Measure(s): The Krippendorff α (K α) was used to assess the interrater reliability, whereas intraclass correlation coefficients (ICCs) were used to assess the test-retest reliability and reliability of live-versus-video scoring. Results: Good reliability was found for the test-retest (ICC = 0.6), and excellent reliability was found for the live-versus-video sessions (ICC = 0.92). Poor reliability was found for the interrater reliability (K α = .38). Conclusions: The good test-retest and high live-versus-video session reliability show that the FMS is a usable tool within 1 rater. However, the low interrater K α values suggest that the FMS within the limits of generalization should not be used indiscriminately to detect deficiencies that place the athlete at greater risk for injury. The FMS interrater reliability may be improved with better training for the rater.

Abstract

To examine the relationship between severity grade for radiography, triple-phase technetium 99m nuclear medicine bone scanning, magnetic resonance (MR) imaging, and computed tomography (CT); clinical severity; and recovery time from a tibial stress injury (TSI), as well as to evaluate interassessor grading reliability.This protocol was approved by the Griffith University Human Research Ethics Committee, the Stanford University Panel on Human Subjects in Medical Research, the U.S. Army Human Subjects Research Review Board, and the Australian Defense Human Research Ethics Committee. Informed consent was obtained from all subjects. Forty subjects (17 men, 23 women; mean age, 26.2 years ± 6.9 [standard deviation]) with TSI were enrolled. Subjects were examined acutely with standard anteroposterior and lateral radiography, nuclear medicine scanning, MR imaging, and CT. Each modality was graded by four blinded clinicians. Mixed-effects models were used to examine associations between image severity, clinical severity, and time to healing, with adjustments for image modality and assessor. Grading reliability was evaluated with the Cronbach α coefficient.Image assessment reliability was high for all grading systems except radiography, which was moderate (α = 0.565-0.895). Clinical severity was negatively associated with MR imaging severity (P ≤ .001). There was no significant relationship between time to healing and severity score for any imaging modality, although a positive trend existed for MR imaging (P = .07).TSI clinical severity was negatively related to MR imaging severity. Radiographic, bone scan, and CT severity were not related to time to healing, but there was a positive trend for MR imaging.

Abstract

To analyse published articles that used interventions aimed at investigating biomechanical/physiological outcomes (ie, intermediate risk factors) for sport injury prevention in order to characterise the state of the field and identify important areas not covered in the literature.PubMed, Cinahl, Web of Science and Embase were searched using a broad search strategy.Only 144 of 2525 articles retrieved by the search strategy met the inclusion criteria. Crossover study designs increased by 175% in the late 1980s until 2005 but have declined 32% since then. Randomised controlled trial (RCT) study designs increased by 650% since the early 1980s. Protective equipment studies (61.8% of all studies) declined by 35% since 2000, and training studies (35.4% of all studies) increased by 213%. Equipment research studied stability devices (83.1%) and attenuating devices (13.5%) whereas training research studied balance and coordination (54.9%), strength and power (43.1%) and stretching (15.7%). Almost all (92.1%) studies investigated the lower extremity and 78.1% were of the joint (non-bone)-ligament type. Finally, 57.5% of the reports studied contact sports, 24.2% collision and 25.8% non-contact sports.The decrease in crossover study design and increase in RCTs over time suggest a shift in study design for injury prevention articles. Another notable finding was the change in research focus from equipment interventions, which have been decreasing since 2000 (35% decline), to training interventions, which have been increasing (213% increase). Finally, there is very little research on overuse or upper extremity injuries.

Abstract

To characterise the nature of the sport injury prevention literature by reviewing published articles that evaluate specific clinical interventions designed to reduce sport injury risks.PubMed, Cinahl, Web of Science and Embase.Only 139 of 2525 articles retrieved met the inclusion criteria. Almost 40% were randomised controlled trials and 30.2% were cohort studies. The focus of the study was protective equipment in 41%, training in 32.4%, education in 7.9%, rules and regulations in 4.3%, and 13.3% involved a combination of the above. Equipment research studied stability devices (42.1%), head and face protectors (33.3%), attenuating devices (17.5%) as well as other devices (7%). Training studies often used a combination of interventions (eg, balance and stretching); most included balance and coordination (63.3%), with strength and power (36.7%) and stretching (22.5%) being less common. Almost 70% of the studies examined lower extremity injuries, and a majority of these were joint (non-bone)-ligament injuries. Contact sports were most frequently studied (41.5%), followed by collision (39.8%) and non-contact (20.3%).The authors found only 139 publications in the existing literature that examined interventions designed to prevent sports injury. Of these, the majority investigated equipment or training interventions whereas only 4% focused on changes to the rules and regulations that govern sport. The focus of intervention research is on acute injuries in collision and contact sports whereas only 20% of the studies focused on non-contact sports.

Abstract

Health care providers must be prepared to manage all potential spine injuries as if they are unstable. Therefore, most sport teams devote resources to training for sideline cervical spine (C-spine) emergencies.To determine (1) how accurately rescuers and simulated patients can assess motion during C-spine stabilization practice and (2) whether providing performance feedback to rescuers influences their choice of stabilization technique.Crossover study.Training studio.Athletic trainers, athletic therapists, and physiotherapists experienced at managing suspected C-spine injuries.Twelve lead rescuers (at the patient's head) performed both the head-squeeze and trap-squeeze C-spine stabilization maneuvers during 4 test scenarios: lift-and-slide and log-roll placement on a spine board and confused patient trying to sit up or rotate the head.Interrater reliability between rescuer and simulated patient quality scores for subjective evaluation of C-spine stabilization during trials (O = best, 10 = worst), correlation between rescuers' quality scores and objective measures of motion with inertial measurement units, and frequency of change in preference for the head-squeeze versus trap-squeeze maneuver.Although the weighted ? value for interrater reliability was acceptable (0.71-0.74), scores varied by 2 points or more between rescuers and simulated patients for approximately 10% to 15% of trials. Rescuers' scores correlated with objective measures, but variability was large: 38% of trials scored as 0 or 1 by the rescuer involved more than 10° of motion in at least 1 direction. Feedback did not affect the preference for the lift-and-slide placement. For the log-roll placement, 6 of 8 participants who preferred the head squeeze at baseline preferred the trap squeeze after feedback. For the confused patient, 5 of 5 participants initially preferred the head squeeze but preferred the trap squeeze after feedback.Rescuers and simulated patients could not adequately assess performance during C-spine stabilization maneuvers without objective measures. Providing immediate feedback in this context is a promising tool for changing behavior preferences and improving training.

Abstract

The rapidly increasing burden of chronic disease is difficult to reconcile with the large, compelling body of literature that demonstrates the substantial preventive and therapeutic benefits of comprehensive lifestyle intervention, including physical activity, smoking cessation and healthy diet. Physical inactivity is now the fourth leading independent risk factor for death caused by non-communicable chronic disease. Although there have been efforts directed towards research, education and legislation, preventive efforts have been meager relative to the magnitude of the problem. The disparity between our scientific knowledge about chronic disease and practical implementation of preventive approaches now is one of the most urgent concerns in healthcare worldwide and threatens the collapse of our health systems unless extraordinary change takes place.The authors believe that there are several key factors contributing to the disparity. Reductionism has become the default approach for healthcare delivery, resulting in fragmentation rather than integration of services. This, in turn, has fostered a disease-based rather than a health-based model of care and has produced medical school curricula that no longer accurately reflect the actual burden of disease. Trying to 'fit' prevention into a disease-based approach has been largely unsuccessful because the fundamental tenets of preventive medicine are diametrically opposed to those of disease-based healthcare.A clinical discipline within medicine is needed to adopt disease prevention as its own reason for existence. Sport and exercise medicine is well positioned to champion the cause of prevention by promoting physical activity.This article puts forward a strong case for the immediate, increased involvement of clinical sport and exercise medicine in the prevention and treatment of chronic disease and offers specific recommendations for how this may begin.

Abstract

To compare head motions that occur when trained professionals perform the head squeeze (HS) and trap squeeze (TS) C-spine stabilization techniques.Cross-over design.Twelve experienced lead rescuers.Peak head motion with respect to initial conditions using inertial measurement units attached to the forehead and trunk of the simulated patient. We compared both HS and TS during lift-and-slide (L&S) and log-roll (LR) placement on spinal board, and agitated patient trying to sit up (AGIT-Sit) or rotate his head (AGIT-Rot). The a priori minimal important difference (MID) was 5 degrees for flexion or extension and 3 degrees for rotation or lateral flexion.The L&S technique was statistically superior to the LR technique. The only differences to exceed the MID were extension and rotation during LR (HS > TS). In the AGIT-Sit test scenario, differences in motion exceeded MID (HS > TS) for flexion, rotation, and lateral flexion. In the AGIT-Rot scenario, differences in motion exceeded MID for rotation only (HS >TS). There was similar intertrial variability of motion for HS and TS during L&S and LR but significantly more variability with HS compared with TS in the agitated patient.The L&S is preferable to the LR when possible for minimizing unwanted C-spine motion. There is little overall difference between HS and TS in a cooperative patient. When a patient is confused, the HS is much worse than the TS at minimizing C-spine motion.

Abstract

Athletic osteitis pubis is a painful and chronic condition affecting the pubic symphysis and/or parasymphyseal bone that develops after athletic activity. Athletes with osteitis pubis commonly present with anterior and medial groin pain and, in some cases, may have pain centred directly over the pubic symphysis. Pain may also be felt in the adductor region, lower abdominal muscles, perineal region, inguinal region or scrotum. The pain is usually aggravated by running, cutting, hip adduction and flexion against resistance, and loading of the rectus abdominis. The pain can progress such that athletes are unable to sustain athletic activity at high levels. It is postulated that osteitis pubis is an overuse injury caused by biomechanical overloading of the pubic symphysis and adjacent parasymphyseal bone with subsequent bony stress reaction. The differential diagnosis for osteitis pubis is extensive and includes many other syndromes resulting in groin pain. Imaging, particularly in the form of MRI, may be helpful in making the diagnosis. Treatment is variable, but typically begins with conservative measures and may include injections and/or surgical procedures. Prolotherapy injections of dextrose, anti-inflammatory corticosteroids and a variety of surgical procedures have been reported in the literature with varying efficacies. Future studies of athletic osteitis pubis should attempt to define specific and reliable criteria to make the diagnosis of athletic osteitis pubis, empirically define standards of care and reduce the variability of proposed treatment regimens.

Abstract

Return-to-play (RTP) decisions are a central component of the Team Physician's clinical work, yet there is little more than anecdotal reference to these in the literature. We recently published a 3-step model for return-to-play medical decision making and, in the current paper, undertook a systematic review of the literature to determine the level of evidence in support of this model.PubMed, Web of Science, and CINAHL electronic databases. Any article specifically related to concussion, head injuries, neck injuries, illness, medical conditions (including cardiovascular and renal), and preparticipation in sport or that reported RTP as a clinical outcome was excluded. Any article that contained a discussion on one of the components of the 3-step decision-based RTP model was included.We reviewed 148 articles that met the criteria for inclusion and found 98 review articles, 39 original articles, 6 case reports, and 5 editorials. Of these, 141 articles mentioned Step 1 of the medical decision-making process for RTP (Medical Factors), 26 mentioned Step 2 (Sport Risk Modifiers), and 20 mentioned Step 3 (Decision Modifiers). Of the 148 articles in total, only 13 focused on RTP as the main subject and the remaining 135 mentioned RTP anecdotally. Of these 13 articles, 5 were reviews, 4 were editorials, and 4 were original research.Although 148 articles we retrieved mention RTP in relation to a specific injury, medical condition, or specific topic, only 13 articles focused specifically on the RTP decision-making process, and 6 of 13 were restricted to Step 1 of the 3-step model (Medical Factors). Return-to-play is a fertile field for research and thought leadership beginning with a focus on the Team Physician's appropriate role in RTP decision making, particularly considering the factors identified in Step 3 (Decision Modification).

Abstract

To identify the nature and extent of research in sport injury prevention with respect to 3 main categories: (1) training, (2) equipment, and (3) rules and regulations.We searched PubMed, CINAHL, Web of Science, Embase, and SPORTDiscus to retrieve all sports injury prevention publications. Articles were categorized according to the translating research into injury prevention practice model.We retrieved 11 859 articles published since 1938. Fifty-six percent (n = 6641) of publications were nonresearch (review articles and editorials). Publications documenting incidence (n = 1354) and etiology (n = 2558) were the most common original research articles (33% of total). Articles reporting preventive measures (n = 708) and efficacy (n = 460) were less common (10% of the total), and those investigating implementation (n = 162) and effectiveness (n = 32) were rare (1% of total). Six hundred seventy-seven studies focused on equipment and devices to protect against injury, whereas 551 investigated various forms of physical training related to injury prevention. Surprisingly, publications studying changes in rules and regulations aimed at increasing safety and reducing injuries were rare (<1%; n = 63) with a peak of only 20 articles over the most recent 5-year period and an average of 10 articles over the preceding 5-year blocks of time.Only 492 of 11 859 publications actually assessed the effectiveness of sports injury prevention interventions or their implementation. Research in the area of regulatory change is underrepresented and might represent one of the greatest opportunities to prevent injury.

Abstract

Return-to-play (RTP) decisions are fundamental to the practice of sports medicine but vary greatly for the same medical condition and circumstance. Although there are published articles that identify individual components that go into these decisions, there exists neither quantitative criteria nor a model for the sequence or weighting of these components within the medical decision-making process. Our objective was to develop a decision-based model for clinical use by sports medicine practitioners.English literature related to RTP decision making.We developed a 3-step decision-based RTP model for an injury or illness that is specific to the individual practitioner making the RTP decision: health status, participation risk, and decision modification. In Step 1, the Health Status of the athlete is assessed through the evaluation of Medical Factors related to how much healing has occurred. In Step 2, the clinician evaluates the Participation Risk associated with participation, which is informed by not only the current health status but also by the Sport Risk Modifiers (eg, ability to protect the injury with padding, athlete position). Different individuals are expected to have different thresholds for "acceptable level of risk," and these thresholds will change based on context. In Step 3, Decision Modifiers are considered and the decision to RTP or not is made.Our model helps clarify the processes that clinicians use consciously and subconsciously when making RTP decisions. Providing such a structure should decrease controversy, assist physicians, and identify important gaps in practice areas where research evidence is lacking.

Abstract

Although the use of standardized cardiovascular (CV) system-focused history and physical examination is recommended for the preparticipation examination (PPE) of athletes, the addition of the electrocardiogram (ECG) has been controversial. Because the impact of ECG screening on college athletes has rarely been reported, we analyzed the findings of adding the ECG to the PPE of Stanford athletes.For the past 15 years, the Stanford Sports Medicine program has mandated a PPE questionnaire and physical examination by Stanford physicians for participation in intercollegiate athletics. In 2007, computerized ECGs with digital measurements were recorded on athletes and entered into a database.Although the use of standardized CV-focused history and physical examination are recommended for the PPE of athletes, the addition of the ECG has been controversial. Because the feasibility and outcomes of ECG screening on college athletes have rarely been reported, we present findings derived from the addition of the ECG to the PPE of Stanford athletes. For the past 15 years, the Stanford Sports Medicine program has mandated a PPE questionnaire and physical examination by Stanford physicians for participation in intercollegiate athletics. In 2007, computerized ECGs with digital measurements were recorded on athletes and entered into a database.Six hundred fifty-eight recordings were obtained (54% men, 10% African-American, mean age 20 years) representing 24 sports. Although 68% of the women had normal ECGs, only 38% of the men did so. Incomplete right bundle branch block (RBBB) (13%), right axis deviation (RAD) (10%), and atrial abnormalities (3%) were the 3 most common minor abnormalities. Sokolow-Lyon criteria for left ventricular hypertrophy (LVH) were found in 49%; however, only 27% had a Romhilt-Estes score of >or=4. T-wave inversion in V2 to V3 occurred in 7%, and only 5 men had abnormal Q-waves. Sixty-three athletes (10%) were judged to have distinctly abnormal ECG findings possibly associated with conditions including hypertrophic cardiomyopathy or arrhythmogenic right ventricular dysplasia/cardiomyopathy. These athletes were offered further testing but this was not mandated according to the research protocol.Six hundred fifty-three recordings were obtained (54% men, 7% African American, mean age 20 years), representing 24 sports. Although 68% of the women had normal ECGs, only 38% of the men did so. Incomplete RBBB (13%), RAD (10%), and atrial abnormalities (3%) were the 3 most common minor abnormalities. Sokolow-Lyon criteria for LVH were found in 49%; however, only 27% had a Romhilt-Estes score of >or=4. T-wave inversion in V2 to V3 occurred in 7% and only 5 men had abnormal Q-waves. Sixty-five athletes (10%) were judged to have distinctly abnormal ECG findings suggestive of arrhythmogenic right ventricular dysplasia, hypertrophic cardiomyopathy, and/or biventricular hypertrophy. These athletes will be submitted to further testing.Mass ECG screening is achievable within the collegiate setting by using volunteers when the appropriate equipment is available. However, the rate of secondary testing suggests the need for an evaluation of cost-effectiveness for mass screening and the development of new athlete-specific ECG interpretation algorithms.

Abstract

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection is an increasing problem in athletic populations, with outbreaks spreading among team members. Due to this elevated risk, several strategies have been adopted from nonsports settings to avoid and to control CA-MRSA outbreaks within athletic teams, including the use of surveillance nasal cultures to identify CA-MRSA carriers for decolonization. We sought to assess the effectiveness of such a surveillance program in reducing CA-MRSA infections over 1 season in a professional football team. In addition, we measured the prevalence of CA-MRSA carriage in players with active CA-MRSA infections and conducted a review of the literature for studies, including CA-MRSA nasal carriage surveys in athletic teams.Prospective cohort.Professional football team, San Francisco 49ers.Players and staff of the 2007 San Francisco 49ers (n = 108).Preseason nasal cultures for CA-MRSA were obtained on players and staff of the San Francisco 49ers. Wound and nasal cultures were performed for all participants with suspected CA-MRSA infections throughout the season.Nasal and wound cultures positive for CA-MRSA.Of 108 total subjects screened on the first day of the 2007 season, 0 cultures were positive for methicillin-resistant Staphylococcus aureus (MRSA). A total of 5 culture-confirmed CA-MRSA infections occurred during the course of the season. Zero of these 5 players had positive MRSA nasal cultures at the time of infection.Despite the success of surveillance nasal screening in controlling MRSA outbreaks in hospital settings, this strategy is ineffective in athletic populations.

Abstract

Human circus arts are gaining increasing popularity as a physical activity with more than 500 companies and 200 schools. The only injury data that currently exist are a few case reports and 1 survey.To describe injury patterns and injury rates among Cirque du Soleil artists between 2002 and 2006.Descriptive epidemiology study.The authors defined an injury as any work-related condition recorded in an electronic injury database that required a visit to the show therapist. Analyses for treatments, missed performances, and injury rates (per 1000 artist performances) were based on a subset of data that contained appropriate denominator (exposure) information (began in 2004).There were 1376 artists who sustained a total of the 18 336 show- or training-related injuries. The pattern of injuries was generally similar across sex and performance versus training. Most injuries were minor. Of the 6701 injuries with exposure data, 80% required < or =7 treatments and resulted in < or =1 completely missed performance. The overall show injury rate was 9.7 (95% confidence interval, 9.4-10.0; for context, published National Collegiate Athletic Association women's gymnastics rate was 15.2 injuries per 1000 athlete-exposures). The rate for injuries resulting in more than 15 missed performances for acrobats (highest risk group) was 0.74 (95% confidence interval, 0.65-0.83), which is much lower than the corresponding estimated National Collegiate Athletic Association women's gymnastics rate.Most injuries in circus performers are minor, and rates of more serious injuries are lower than for many National Collegiate Athletic Association sports.

Abstract

Tibial stress fractures increasingly affect athletes and military recruits, with few known effective management options. Electrical stimulation enhances regular fracture healing, but the effect on stress fractures has not been definitively tested.Capacitively coupled electric field stimulation will accelerate tibial stress fracture healing.Randomized controlled trial; Level of evidence, 1.Twenty men and 24 women with acute posteromedial tibial stress fractures were referred from local clinicians. Subjects were randomly assigned active or placebo capacitively coupled electric field stimulation to be applied for 15 hours per day until healed, given supplemental calcium, and instructed to rest from provocative training. Healing was confirmed when hopping to 10 cm for 30 seconds could be achieved without pain.No difference in time to healing was detected between treatment and placebo groups. Women in the treatment group healed more slowly than did the men (P = .05). Superior treatment compliance was associated with reduced time to healing (P = .003). Rest noncompliance was associated with increased time to healing (P = .05).Whole-group analysis did not detect an effect of capacitively coupled electric field stimulation on tibial stress fracture healing; however, greater device use and less weightbearing loading enhanced the effectiveness of the active device. More severe stress fractures healed more quickly with capacitively coupled electric field stimulation.Although the use of capacitively coupled electric field stimulation for tibial stress fracture healing may not be efficacious for all, it may be indicated for the more severely injured or elite athlete/recruit whose incentive to return to activity may motivate superior compliance.

Abstract

New fields such as bioengineering are exploring the role of the physical sciences in traditional biological approaches to problems, with exciting results in device innovation, medicine, and research biology. The integration of mathematics, biomechanics, and material sciences into the undergraduate biology curriculum will better prepare students for these opportunities and enhance cooperation among faculty and students at the university level. We propose the study of sports science as the basis for introduction of this interdisciplinary program. This novel integrated approach will require a virtual human performance laboratory dual-hosted in Sweden and the United States. We have designed a course model that involves cooperative learning between students at Göteborg University and Stanford University, utilizes new technologies, encourages development of original research and will rely on frequent self-assessment and reflective learning. We will compare outcomes between this course and a more traditional didactic format as well as assess the effectiveness of multiple web-hosted virtual environments. We anticipate the grant will result in a network of original faculty and student research in exercise science and pedagogy as well as provide the opportunity for implementation of the model in more advance training levels and K-12 programs.

Abstract

A stress fracture is a partial or complete bone fracture that results from repeated application of stress lower than the stress required to fracture the bone in a single loading. Otherwise healthy athletes, especially runners, sustain stress injuries or fractures. Prevention or early intervention is the preferable treatment. However, it is difficult to predict injury because runners vary with regard to biomechanical predisposition, training methods, and other factors such as diet, muscle strength, and flexibility. Stress fractures account for 0.7% to 20% of all sports medicine clinic injuries. Track-and-field athletes have the highest incidence of stress fractures compared with other athletes. Stress fractures of the tibia, metatarsals, and fibula are the most frequently reported sites. The sites of stress fractures vary from sport to sport (eg, among track athletes, stress fractures of the navicular, tibia, and metatarsal are common; in distance runners, it is the tibia and fibula; in dancers, the metatarsals). In the military, the calcaneus and metatarsals were the most commonly cited injuries, especially in new recruits, owing to the sudden increase in running and marching without adequate preparation. However, newer studies from the military show the incidence and distribution of stress fractures to be similar to those found in sports clinics. Fractures of the upper extremities are relatively rare, although most studies have focused only on lower-extremity injuries. The ulna is the upper-extremity bone injured most frequently. Imaging plays a key role in the diagnosis and management of stress injuries. Plain radiography is useful when positive, but generally has low sensitivity. Radionuclide bone scanning is highly sensitive, but lacks specificity and the ability to directly visualize fracture lines. In this article, we focus on magnetic resonance imaging, which provides highly sensitive and specific evaluation for bone marrow edema, periosteal reaction as well as detection of subtle fracture lines.

Who said medicine means never having to say you're sorry?PHYSICIAN AND SPORTSMEDICINEMatheson, G. O.2005; 33 (12): 2-2

Abstract

Your mother said it, your teachers reiterated it, and you've heard it countless times: Everyone makes mistakes. So why do we doctors have such difficulty admitting that? More important, how do we respond to our patients after we make mistakes?

Abstract

Environmental conditions that day in Vancouver did not at all bring to mind heatstroke. Ambient temperature stayed below 21 C (70 F), with a gentle breeze off the bay. What's more, the event was a mere 10-km "fun run." Yet the medical tent saw several cases of hyperthermia-and I had the sore ribs to prove it.

Abstract

Perhaps primary among the gatekeepers of injury prevention stands the team physician. But team physicians typically are more geared toward treating injuries than preventing them, and we need to bolster the prevention arm.

Abstract

I just returned from Oslo and the stimulating First International Congress on Sports Injury Prevention. I'm excited by the quality of the information presented and the dedication of countless experts from many countries to bring this crucial topic to the fore. I'm also pleased to promote a message that has been central to the mission of this journal: to not only treat sports-related injury and illness but also to encourage physical activity as a means for both treating and preventing disease.

Steroids in sports - Are drugs the only ones being used?PHYSICIAN AND SPORTSMEDICINEMatheson, G. O.2005; 33 (5): 6-6

Abstract

Given the nature of the testimony at the Congressional hearings on anabolic steroids in baseball in March, I continue to harbor concerns over drug use and other harmful trends in sports (see my editorials in the January through March issues). But now I'm worried that current sports ethics, already impaired by drugs, have also tainted those who care for the athletes.

Abstract

This study seeks to show that in the case of a patient not responding to nonoperative measures for the treatment of anterior knee pain, arthroscopic release of a symptomatic infrapatellar plica can successfully resolve the disability.We report a retrospective study of 12 cases of anterior knee pain not responding to nonoperative treatment that underwent isolated infrapatellar plica resection without other noted knee pathology.Patients were evaluated and treated in an outpatient orthopedic sports medicine clinic.Any patient who presented with anterior knee pain, underwent subsequent arthroscopy, and was treated by isolated resection of the infrapatellar plica was included in the study.The surgical procedure involved arthroscopic division of the infrapatellar plica at its attachment on the superior intercondylar notch of the femur.Patients were reviewed at least 12 months following the date of surgery. Two subjective knee scales were used to assess knee function.A subjective scale used in prior studies assessing symptomatic medial plica demonstrated 91% percent (11 of 12) excellent (6) or good (5) outcomes at follow-up greater than 1 year. The Knee Injury and Osteoarthritis Outcome Scores of knee function on the subscales of pain, symptoms, activities of daily living, sports activity, and quality of life were 97, 96, 99, 99, and 87, respectively.These cases demonstrate a potential role for the infrapatellar plica as a cause of anterior knee pain. A prospective study is warranted to measure causality.

Sports gone wild - Part 1: Are we part of the problem?PHYSICIAN AND SPORTSMEDICINEMatheson, G. O.2005; 33 (2): 7-7

Abstract

You've seen it all on the news: players assaulting fans, fans assaulting athletes, college footbrawl games, crass posturing, off-field criminal-or at least debasing-behavior, rampant drug use. In short, athletes whom we look to for inspiration are instead acting as though they live above the laws that govern civil society. What's gone wrong? And, more important, how have sports medicine professionals contributed to it?

Abstract

Every major newspaper and magazine has headlined the BALCO scandal involving Barry Bonds, Jason Giambi, Marion Jones, and performance-enhancing drugs. Few of us are surprised at the allegations. But the extent of the apparent lying and cheating at the highest levels is devastating. That sport can and will remain intact because of its entertainment value is a given-as is the response by major sports organizations that smells more like an attempt to protect market share than a step to protect athletes and athletics.

Abstract

Our medical system is principally based on disease. Fair enough. If patients have a problem that decreases function, they see a doctor, a diagnosis follows, and an attempt is made to restore their capacity to normal. When patients see a doctor, the physician's main concern is the presence or absence of disease and whether they can be treated in some fashion.

Abstract

In medicine, when we see something awry-or even something that might go awry-we tend to fix it. But can this tendency create its own problems? A friend's recent experience got me thinking about the fine line between preventive medicine and iatrogenic harm.

Abstract

The purpose of this study was twofold: to determine if asymptomatic elite distance runners exhibit stress reactions of the tibia on MR images and to determine if the presence of bone stress lesions predicts later development of symptomatic tibial stress injuries.Signs of a tibial stress reaction were found on MRI in 43% of the 21 asymptomatic college distance runners in this study. The presence of these changes was not found to be a predictor of future tibial stress reactions or stress fractures. Our findings underscore the importance of correlating MRI findings with clinical findings before making therapeutic decisions.

Abstract

These are difficult times to be writing about the Olympic Games, now returning to their birthplace in Athens, Greece. The specter of athlete drug scandals (see News Briefs) on the heels of ethical lapses within the IOC itself and the role of sleazy "supplement" manufacturers and promoters have tarnished the Olympic rings. The vast scope of the 28th Olympiad, delays in construction, and concerns regarding security might be the final straw in what seems to have become an entertainment extravaganza rather than a demonstration of courage, athleticism, and perseverance.

Abstract

Sports medicine, like many other branches of medicine, has always had two sides: treatment and prevention. Treating acute injuries and illnesses that prevent participation in sports and exercise has been front and center in clinical medicine, while prevention is something we spend more time talking about than actually doing.

Abstract

To review available evidence establishing the validity of the preparticipation evaluation (PPE) as a method for screening health risk prior to participation in exercise and sport. Specific emphasis was placed on reviewing original research evaluating methods to screen participants for risk of sudden cardiovascular death. Literature on the current state of the PPE as a screening tool for athletic participation was examined.Electronic databases were searched for articles relating to mass screening for sports participation and sudden cardiac death in athletes published up to January 2004. Databases searched included Medline (OVID Web, 1966-2004), PubMed (1966-2004), Sport Discuss (1975-2004), Current Contents, CISTI Source (1993-2004), Cochrane Database of Systematic Reviews, and EBM Reviews. Additional references from the bibliographies of retrieved articles were also reviewed.All study designs were retrieved, but only those studying athletes and/or student-athletes under age 36 years were reviewed. Of the original research retrieved, the majority of the articles sought to establish incidence or prevalence of cardiovascular causes of sudden death in athletes or the validity of various screening tools. Original research articles seeking to establish the current use of the PPE in all its various forms were also reviewed. All of the articles selected for review consisted of type II, population-based data.The initial literature search identified 639 papers. Of these, 310 articles that met the selection criteria were reviewed, and 25 articles were identified as original research directly relating to the PPE. All of these contained type II evidence-population-based clinical studies. The majority of the literature on the PPE consists of type III evidence-case-based opinion papers and position papers from respected authors and sports medicine societies and reports of expert committees. This literature was also reviewed, but only original research relevant to the PPE is reported in this article. The majority of these studies examined cardiovascular diseases and screening procedures.The 5 studies that assessed the format or effectiveness of the PPE concluded that it was inadequate. The format of the PPE is not standardized and does not consistently address the American Heart Association recommendations for cardiovascular screening history and physical exams. A variety of health care professionals, some without proper training, administer the PPE. The 12 original studies that looked at specific cardiovascular screening techniques were divided on the effectiveness of history, physical examination, electrocardiogram, and echocardiography for detecting cardiovascular risks for sudden death in athletes.A PPE is required by most sport organizations in America, but research as to its effectiveness is very limited. PPEs have been mandatory in Italy for many years, and we can draw on some the data recorded over this time. Otherwise, very few studies in America or elsewhere have been performed on the PPE process. The research available indicates that the PPE is not implemented adequately or uniformly. An opportunity exists to create a standardized, validated PPE that meets medical standards for quality and provides sensitive, specific screening of potential participants in sport and exercise.

Patient care is more than skin deep - Medical coverage from the PPE to HPVPHYSICIAN AND SPORTSMEDICINEMatheson, G. O.2004; 32 (5): 2-2

Abstract

We all know that sports medicine involves much more than sprains, strains, and fractures. We at The Physician and Sportsmedicine have always stressed the importance of treating the entire patient, and this concept has been foremost in two significant projects underway this year: (1) the third edition of The Preparticipation Physical Evaluation (PPE), set to be released in August, and (2) the launch of our Sports Dermatology Series this month.

Abstract

Prostate cancer is a leading cause of cancer morbidity and mortality in men. In addition to improved treatments, strategies to reduce disease risk are urgently required. This review summarises the literature that examines the association between exercise and prostate cancer risk. Between 1989 and 2001, 13 cohort studies were conducted in the US and internationally. Of these, nine showed an association between exercise and decreased prostate cancer risk. Five of 11 case-control studies conducted between 1988 and 2002 reported an association between decreased risk of prostate cancer and high activity levels. Considering all studies performed between 1976 and 2002, 16 out of 27 studies reported reduced risk in men who were most active; in nine out of 16 studies the reduction in risk was statistically significant. Average risk reduction ranged from 10-30%. In aggregate, this evidence suggests a probable link between increased physical exercise and decreased prostate cancer risk. The ability of exercise to modulate hormone levels, prevent obesity, enhance immune function and reduce oxidative stress have all been postulated as mechanisms that may underlie the protective effect of exercise. Exercise may also be of benefit in men undergoing treatment for prostate cancer. Overall, study design and control of potential confounding factors varied greatly among studies, possibly contributing to the variation in results. Epidemiological studies that are better controlled, larger in scale and more carefully designed may help to more fully clarify the relationship between exercise and prostate cancer. In addition, intervention trials that test whether exercise programmes can reduce prostate cancer risk are currently underway to rigorously test the ability of exercise to reduce prostate cancer incidence.

Abstract

Those of us in primary care sports medicine love variety. Where else could you treat, in the course of a workday, a 14-year-old gymnast with back pain, an elite college soccer player with a perplexing stress fracture-and potential eating disorder-a 50-year-old heart patient, and a sedentary widow with knee pain? We have the wonderful opportunity to treat the whole patient, and to treat members of the whole patient population.

Abstract

I've come to realize something that should profoundly affect the way we approach sports medicine: Twenty years ago, exercise and sports were virtually synonymous with health. Today, exercise still clearly promotes health,(1) but competitive sports often may not.(2-4) We need to own up to that fact, and shape our practices to address it.

Abstract

This issue marks the official 30th anniversary of The Physician and Sportsmedicine (PSM). Over the past 30 years, PSM has published 358 issues of the journal, which adds up to about 400 million individual copies. That's a decent-sized stack.

Abstract

We physicians recommend exercise to our patients all the time, but do we really know how best to define it, measure it, and prescribe it? This month we're launching a new four-part series to answer those questions. The series, "The Science of Exercise Physiology," coordinated by editorial board member Howard G. (Skip) Knuttgen, PhD, demonstrates how to apply the building blocks of sports science toward everyday clinical practice.

Abstract

To assess the reliability and discriminate validity of a new screening instrument for college student athletes.518 Stanford University students completed the proposed instrument (College Health Related Information Survey-CHRIS-73), which was based on the Juvenile Wellness and Health Survey (JWHS-76) but re-designed to assess mental health domains relevant to college athletes.Factor analysis yielded four factors: mental health problems, eating problems, risk behaviors, and performance pressure. Factors were internally consistent, reasonably independent, and clearly discriminated between athletes and non-athletes, and males and females.This study supports the CHRIS-73 as a useful screen for assessing mental health problems among college student athletes.

Abstract

2003 marks the 30th year of The Physician and Sportsmedicine (PSM). I remember reading the journal in its first decade, and being impressed with its wide coverage of topics related to exercise, sports, human performance, and health. Of course, I'm even more impressed with its scope and breadth now, but I no longer remain impartial. Join us in celebrating all year long.

Abstract

Let's have a show of hands. Who feels tied down-rather than liberated-by all the new electronic gadgets? Yay? Nay? Can't even raise a hand because you're going through your voice mail messages on your cell phone as you navigate rush-hour traffic while slurping a latté?

Is it OK to be a fan and a team physician?PHYSICIAN AND SPORTSMEDICINEMatheson, G. O.2002; 30 (9): 2-2

Abstract

The patient population we serve in sports medicine is much different than that of other branches of medicine. Physicians express empathy (understanding, sympathy, and compassion) toward those with disease and illness. Empathy is considered an essential virtue of the ethical medical care provider, along with veracity and fidelity. Empathy provides a healthy balance between anxiety and coldness, intimacy and detachment, subjectivity and objectivity. Each physician seeks the line that separates these qualities.

Abstract

One of every 4 or 5 primary care visits is for a musculoskeletal problem. Yet undergraduate and graduate training for this burden of illness continues to constitute typically less than 5% of the medical curriculum. This is an area of clear concern, but also one in which sports medicine practitioners can assume leadership.

Abstract

For many years, physiologists have puzzled over the observation that, during maximum aerobic exercise, high-altitude natives generate lower-than-expected amounts of lactate; the higher the altitude, the lower the postexercise blood lactate peak. This paradoxical situation may be caused mainly by upregulated metabolic control contributions from cell ATP demand and ATP supply pathways.

Abstract

How many of you, following an injury to a star player, are asked a question like this from a teammate, parent, coach, or administrator: "Will she be able to play in Saturday's game?" Nothing wrong with the query, right? We get it all the time. The intriguing aspect is that often it's the first question out of that person's mouth. Not "How is she?" or "How will this affect her life down the road?" In fact, the question has little to do with the athlete's health, which should be our foremost concern.

Abstract

Want to generate a little excitement at your next conference? Ask family physicians or orthopedists, "What specialty is best suited to act as team physicians?" As an editor, I've had the opportunity to be a "fly on the wall" when this subject has been debated. I often talk to family physicians who feel they have a more holistic approach and a wider range of skills to meet the vast array of problems encountered by the physically active. As they point out, musculoskeletal injuries, and particularly those that need surgery, are only one, small part of sports medicine.

Abstract

Athletic tape has been commonly reported to lose much of its structural support after 20 min of exercise. Although many studies have addressed the functional performance characteristics of athletic tape, its mechanical properties are poorly understood. This study examines the failure and fatigue properties of several commonly used athletic tapes.A Web-based survey of professional sports trainers was used to select the following three tapes for the study: Zonas (Johnson & Johnson), Leukotape (Beiersdorf), and Jaylastic (Jaybird & Mais). Using a hydraulic material testing system (MTS), eight samples of each tape were compared in three different mechanical tests: load-to-failure, fatigue testing under load control, and fatigue testing under displacement control. Differences in tape microstructure were used to interpret the results of the mechanical tests.Significant differences (P < 0.001) in failure load, elongation at failure, and stiffness were found from failure tests. Significant differences were also found (P < 0.001) in fatigue behavior under both modes of control. As a representative example, in one normalized displacement control fatigue test after 20 min of cycling, 21% (Zonas), 29% (Leukotape), and 57% (Jaylastic) of the mechanical support was lost. After cycling, all tapes loaded to failure showed increased stiffness (P < 0.001), indicating significant energy absorption during cycling. Observed differences in the tapes' microstructure were qualitatively consistent with the measured differences in their mechanical properties.In understanding the shortcomings of currently available tapes, the results of these tests can now be used as benchmarks with which to compare and develop future tape designs. Ultimately, these improved tapes should reduce ankle injuries among athletes.

Abstract

As the world looks toward Salt Lake City this month, it's satisfying to note the direction of the International Olympic Committee's (IOC's) new leadership. IOC president Jacques Rogge, MD, of Belgium, elected last July, favors a simpler Olympic Games and a greater focus on the athletes' health.

How are you investing your time?PHYSICIAN AND SPORTSMEDICINEMatheson, G. O.2002; 30 (1): 7-7

Abstract

Reflections at the beginning of this year stand worlds apart from those of a year ago. In the past 12 months we've seen a rapid decline in global stability, terrorist acts on American soil unparalleled in magnitude or horror, an economic recession, and the virtual dissolution of Internet start-up companies. As we bid adieu to 2001, prospects of improvement are, thankfully, brighter.

Abstract

Mandatory preparticipation examinations (PPE) are labor intensive, offer little routine health maintenance and are poor predictors of future injury or illness. Our objective was to develop a new PPE for the Stanford University varsity athletes that improved both quality of primary and preventive care and physician time efficiency. This PPE is based on the annual submission, by each athlete, of a comprehensive medical history questionnaire that is then summarized in a two-page report for the examining physician. The questionnaire was developed through a search of MEDLINE from 1966 to 1997, review of PPE from 11 other institutions, and discussion with two experts from each of seven main content areas: medical and musculoskeletal history, eating, menstrual and sleep disorders, stress and health risk behaviors. Content validity was assessed by 10 sports medicine physicians and four epidemiologists. It was then programmed for the World Wide Web (http:// www.stanford.edu/dept/sportsmed/). The questionnaire demonstrated a 97 +/- 2% sensitivity in detecting positive responses requiring physician attention. Sixteen physicians administered the 1997/98 PPE; using the summary reports, 15 found improvement in their ability to provide overall medical care including health issues beyond clearance; 13 noted a decrease in time needed for each athlete exam. Over 90% of athletes who used the web site found it "easy" or "moderately easy" to access and complete. Initial assessment of this new PPE format shows good athlete compliance, improved exam efficiency and a strong increase in subjective physician satisfaction with the quality of screening and medical care provided. The data indicate a need for improvement of routine health maintenance in this population. The database offers opportunities to study trends, risk factors, and results of interventions.

Abstract

Most of us who enjoy sports can recall one or two close brushes with catastrophe. Or at least we can remember an incident that gives us chills when we reflect back on it. I have a few such memories, mostly related to mountaineering and skiing. The most indelible one dates back to a day when I was skiing at high speed down a steep slope in whiteout conditions. Without realizing it I flew off a snowy lip and became airborne, unaware I had rotated upside down. I landed directly on my head and felt a "crack" when my neck flexed forward. After picking myself up, I realized I was all right, but I still shudder when I think how close I came to breaking my neck.

Abstract

You, our readers, don't often think of yourselves as being at the forefront of a medical trend-but, in fact, you are. That trend is the gradual emergence of a "health model" of medicine, with its roots in sports medicine and similar health-oriented clinical disciplines. You practice in this mode whenever you offer advice on prevention of disease or injury, prescribe exercise for fitness or rehabilitation, or find a way to help patients with asthma or osteoarthritis remain active.

Abstract

Only a small fraction of the revolutionary changes in medical education made possible by the World Wide Web have yet been realized. Ways of working, communicating-even thinking-are rapidly evolving in directions difficult to predict.

Abstract

Preventing stress fractures requires knowledge of the risk factors that predispose to this injury. The aetiology of stress fractures is multifactorial, but methodological limitations and expediency often lead to research study designs that evaluate individual risk factors. Intrinsic risk factors include mechanical factors such as bone density, skeletal alignment and body size and composition, physiological factors such as bone turnover rate, flexibility, and muscular strength and endurance, as well as hormonal and nutritional factors. Extrinsic risk factors include mechanical factors such as surface, footwear and external loading as well as physical training parameters. Psychological traits may also play a role in increasing stress fracture risk. Equally important to these types of analyses of individual risk factors is the integration of information to produce a composite picture of risk. The purpose of this paper is to critically appraise the existing literature by evaluating study design and quality, in order to provide a current synopsis of the known scientific information related to stress fracture risk factors. The literature is not fully complete with well conducted studies on this topic, but a great deal of information has accumulated over the past 20 years. Although stress fractures result from repeated loading, the exact contribution of training factors (volume, intensity, surface) has not been clearly established. From what we do know, menstrual disturbances, caloric restriction, lower bone density, muscle weakness and leg length differences are risk factors for stress fracture. Other time-honoured risk factors such as lower extremity alignment have not been shown to be causative even though anecdotal evidence indicates they are likely to play an important role in stress fracture pathogenesis.

Abstract

One of the pleasures of working in sports medicine is being part of the energy and excitement as this international, multidisciplinary field develops. Bringing this to you, the clinician-focusing on the practical implications of the field's discoveries-is the overall mission of The Physician and Sportsmedicine. One of the major links in this process-the journal's eyes and ears-is our editorial board. (Please turn to page 5 to see the list of our new and returning board members.).

Abstract

Previous studies of brain glucose metabolism in people indigenous to high-altitude environments uncovered two response patterns: Quechuas native to the high Andes of South America sustained modest hypometabolism in most brain regions interrogated, whereas Sherpas, native to the Himalayas and considered by many biologists to be most effectively high-altitude adapted of all humans, showed brain metabolic patterns similar to lowlanders, with no acclimation effects noted. In the present study, the database was expanded to include hypoxia acclimation effects in lowlanders. Positron emission tomography (PET) and [(18)F]-2-deoxy-2-fluro-D-glucose (FDG) imaging techniques were used to assess regional cerebral glucose metabolic rates (rCMR(glc)) in six US marines (Caucasian lineage) before and after a 63-day training program for operations at high altitudes ranging from 10,500 to 20,320 ft. Significant changes in rCMR(glc) were found for 7 of 25 brain regions examined. Significant decreases in absolute cerebral glucose metabolism after high-altitude exposure were found in five regions: three frontal, the left occipital lobe, and the right thalamus. In contrast, for the right and left cerebellum significant increases in metabolism were found. The magnitudes of these differences, in terms of absolute metabolism, were large, ranging from 10 to 18%. Although the results may not be solely the result of lower oxygen levels at high altitude, these findings suggest that the brain of healthy human lowlanders responds to chronic hypoxia exposure with precise, region-specific fine tuning of rCMR(glc). The observed short-term hypoxia acclimation responses in these lowlanders clearly differ from the long-term hypoxia adaptations found in brain metabolism of people indigenous to high-altitude environments.

Abstract

A substantial part of our work as physicians involves treating sport- and exercise-related injuries. We also recommend exercise, knowing that it will result in a certain number of acute and overuse injuries. As team physicians, we attend competitive events despite awareness that participants in certain sports run a high risk of significant harm. So then, where do we stand in relation to the Hippocratic Oath: "First do no harm"?

Abstract

It is popular among modern scholars in the humanities to describe "myths" or "metaphors" that guide our lives and actions. The corporate literature calls these "paradigms." Whatever the terminology, people more or less consciously use these types of mental structures to interpret events, set priorities, and interact with others. The metaphors that underlie sports medicine emphasize health, functional capacity, and human performance, and our ability to enhance and preserve these throughout life. They appeal to patients in much the same way "complementary and alternative" therapies do; yet sports medicine is supported by the same scientific foundation as other medical disciplines.

Abstract

Stress fractures are one of the most common overuse injuries seen in athletes, accounting for up to 20% of all injuries presented to sports medicine clinics. Runners are particularly prone to these injuries, however, it is difficult to predict injury as there is usually a critical interplay between the athlete's biomechanical predisposition, training methods, and other factors such as diet, and muscle strength and flexibility. This article will discuss the key clinical findings for the majority of stress fractures encountered in a sports medicine practice. A classification scheme will also be described that will allow the clinician to make appropriate treatment decisions based on the degree of risk for each injury.

Abstract

The purpose of this study was to determine the acute physiologic effects of two electrical stimulation protocols commonly used for muscle rehabilitation. Surface electrodes were used to provide 12 stimulations of the calf musculature. In protocol A the duty cycle was fixed at 1:1 (10-second stimulation: 10-second rest); for protocol B it was 1:5 (10-second stimulation: 50-second rest). We continuously recorded isometric plantarflexor force in six healthy male subjects during stimulation using a load cell connected to a foot pedal ergometer. Metabolic changes in the stimulated gastrocnemius muscle were monitored in the supine position using 31P-NMR spectroscopy (Phillips 1.5 tesla NMR machine). Relative changes in phosphocreatine (PCr), inorganic phosphate (Pi), and intracellular pH (pHi) were obtained during stimulation and recovery, using a 1.5 cm RF surface antenna. Over the 12 stimulations, protocol A produced a significantly (p < 0.001), greater force decline (protocol A: 30.4 +/- 1.3%, protocol B: 13 +/- 0.8%); a significantly (p < 0.005), greater increase in Pi/PCr (protocol A: 210%, protocol B: 50%); and a significantly (p <0.001), lower pHi (protocol A: 6.8 +/- 0.16, protocol B: 7.03 +/- 0.12). We conclude that the shorter duty cycle produces more fatigue throughout the stimulation period, possibly as a result of greater intracellular acidosis and reduced availability of the high energy phosphate PCr. The clinical application of this finding relates to the selection of a stimulation protocol that maximizes strength gains in atrophic vs healthy muscle.

Abstract

The observation that the amount of lactate formed during hypobaric hypoxia decreases with the severity of hypoxia has become known as the "lactate paradox." We used noninvasive 31P magnetic resonance spectroscopy (MRS) to further probe this problem and explore the nature of muscle metabolism during rest-exercise-recovery transitions in Sherpas indigenous to the high Himalayas of Nepal. MRS data were obtained using a whole body 1-m bore, 1.5-T Phillips Gyroscan spectrometer. Muscle-specific localization of MRS data acquisition was achieved by means of a modified image-selected in vivo spectroscopy sequence (ISIS). The spectra acquired from the medial and lateral gastrocnemius muscle, rich in fast-twitch fibers, were well constrained by selective excitation and by the boundary of the leg. The spectra from a third region contained signals predominantly from the soleus, a muscle formed mainly of slow-twitch fibers. We quantified relative concentration changes in phosphocreatine (PCr), Pi, and ATP during a series of calf muscle work bouts; free ADP concentrations were calculated on the assumption that the creatine phosphokinase reaction was always essentially at equilibrium. Hydrogen ion concentrations were calculated from the chemical shift of Pi, which represents the equilibrium between mono- and diprotonated phosphate. Plantar flexion was quantified using a calf muscle ergometer designed for operation within a 1-m whole body magnet. We found that the concentration of ATP was rigorously regulated and thus did not change despite large changes in ATP turnover rates required through exercise. The relative concentrations of PCr and Pi were linear functions of the percent maximum work rate of the lateral and medial gastrocnemius, but on transition to exercise the fractional concentration changes in these metabolites were much less than the fractional change in muscle ATP turnover rates. The relationship between muscle ATP turnover rate and free ADP concentration was complex; again, a kinetic order of 1 was not observed. In contrast to the gastrocnemius, the soleus muscle sustained much smaller changes in the concentrations of these crucial metabolites during rest-work-recovery transitions. Unlike the situation in most other muscles rich in fast-twitch fibers characterized by lactate-associated acidosis during muscle work, the intracellular pH in gastrocnemius of Sherpas was stable through these protocols, which is consistent with the low lactate production (i.e., with the lactate paradox) observed in indigenous highlanders.

Abstract

This study was undertaken to investigate the use of vibromyography (VMG) as a tool for quantifying skeletal muscle force production. Fourteen healthy volunteers were pretested using a Cybex isokinetic dynamometer to determine their isometric quadricep maximum voluntary contraction (MVC) values. On the basis of these results, the subjects were separated into two groups: high-force ("HF" MVC mean = 289 ft.lb., range 254-330) and low-force ("LF" MVC mean = 154 ft.lb., range 101-198). A vibromyographic piezoelectric accelerometer (Dytran 3115A) and electromyographic (EMG) surface electrodes were affixed to the rectus femoris muscle and recordings were obtained at 20, 40, 60, 80, and 100% MVC. Root mean squares, median and mean values were computed from digitized data in the time domain while peak values were calculated from a fast Fourier transform for both the VMG and EMG data. A two-way repeated measures MANOVA using relative values and a linear regression model using absolute values were studied using BMDP and MiniTab software. Linear correlations were found between quadricept force and all EMG variables (R2 range 0.71-0.90) except peak (R2 = 0.39). The relationship between VMG and force was less linear (R2 range 0.19-0.69) because VMG values reach a plateau or even drop at 80% and 100% MVC. The HF-LF group differences were significant (p < 0.05), for all VMG values with the exception of root mean squares, but were not significant (p > 0.05) for all four EMG values. This study shows that, while EMG can discriminate force production within a given subject, VMG is a better discriminator of absolute muscle force values between subjects, particularly up to 60% MVC.

Abstract

It is common practice to measure serum ferritin levels in endurance athletes because of the belief that low iron stores may compromise performance. The direct relationship between endurance performance and iron deficiency anemia is well known, but there are theoretical reasons to believe that endurance performance may be adversely affected by low iron stores even in the absence of frank anemia. The purpose of this article is to provide a critical review of the scientific evidence relating low iron stores to endurance performance.Medline was searched using MeSH for articles related to ferritin and endurance published since 1985. Additional references were reviewed from the bibliographies of the retrieved articles.All clinical study designs were reviewed as well as relevant animal studies. Conclusions regarding endurance performance in humans were limited to data from clinical studies.In reviewing the literature, the relative strengths of the study designs were examined carefully. Particular attention of the effectiveness of each study in isolating ferritin as the key independent variable. Dependent measures of endurance capacity were also evaluated.Eight studies isolated serum ferritin as the experimental variable. Only one study reported a significant improvement in endurance performance (time to exhaustion) in subjects with low ferritin levels treated with oral iron, but this finding may have been magnified by an unexplained decrease in time to exhaustion in the control group. Iron dosages differed in the studies reviewed. Two additional studies that reported increases in performance parameters following increases in ferritin were confounded by concomitant increases in hemoglobin levels.Iron supplementation can raise serum ferritin levels, but increases in ferritin concentration, unaccompanied by increases in hemoglobin concentration, have not been shown to increase endurance performance. Of concern to the clinician is that athletes with low ferritin levels but hemoglobin in the low-normal range may have iron deficiency anemia responsive to iron supplementation. Low ferritin with hemoglobin in the mid- to upper normal range is at best a relative indication for iron supplementation: low ferritin with hemoglobin in the low normal range is a stronger, yet still relative, indication for iron supplementation in athletes.

Abstract

The use of local corticosteroid injections for the treatment of Achilles tendonitis is controversial. Some authors advocate their use based on efficacy in accelerating the healing process of Achilles tendonitis; others feel the associated side effects should preclude their use altogether. The purpose of this study was to comprehensively review and critically appraise the available literature in order to examine the evidence concerning this clinical dilemma.MEDLINE was searched using MeSH and textwords for English- and French-language articles related to Achilles tendonitis and corticosteroids published since 1966. Additional references were reviewed from the bibliographies of the retrieved articles. The total number of articles reviewed was 145.All clinical study designs were included as well as related animal studies using experimental and quasi-experimental designs.In reviewing the literature, particular attention was paid to the relative strengths of the different study designs. From these data, the factors associated with effectiveness and safety of injected corticosteroids were examined.The only rigorous studies (one randomized controlled trial, one cohort study) showed no benefit of corticosteroids over placebo. In animal studies, corticosteroid injections decrease adhesion formation, temporarily weaken the tendon if given intratendinously, but have no effect on tendon strength if injected into the paratenon. The overall incidence of side effects with locally injected corticosteroids is approximately 1%. Most side effects are temporary, but skin atrophy and depigmentation can be permanent. Although there are many case reports of Achilles tendon rupture following local corticosteroid injection, there are no published rigorous studies that evaluate the risk of rupture with or without corticosteroid injection.There are insufficient published data to determine the comparative risks and benefits of corticosteroid injections in Achilles tendonitis. The decreased tendon strength with intratendinous injections in animal studies suggests that rupture may be a potential complication for several weeks following injection.

Abstract

This study comprehensively reviews and critically appraises recent literature on cross-country skiing injuries. Particular attention was paid to the study design when reviewing the literature, thereby producing a measure of internal and external validity. From these data, the factors associated with the aetiology, frequency, site distribution and types of cross-country skiing injuries are examined. The incidence of injury in cross-country skiing is estimated to be between 0.49 and 5.63 per 1000 skier days. The most common injuries are medial collateral ligament sprains of the knee, and ulnar collateral ligament sprains of the thumb. Overuse and cold injuries (e.g. hypothermia and frostbite) appear to be common as well, although the data do not provide an estimate of incidence. Comments in the literature on prevention of these injuries are mainly empirical: they recommend safer equipment, wise choice of terrain and a general increase in skier awareness of ways to prevent injury. However, rigorous studies that adequately evaluate preventive intervention strategies have yet to be conducted. Cross-country skiing is relatively safe and a suitable activity for physical fitness and rehabilitation. In the future, studies employing an analytical design will be required to evaluate the effectiveness of injury prevention intervention strategies.

Abstract

A common technique employed in flatwater kayak and canoe races is "wash riding", in which a paddler positions his/her boat on the wake of a leading boat and, at a strategic moment, drops off the wake to sprint ahead. It was hypothesized that this manoeuver was energy efficient, analogous to drafting in cycling. To study this hypothesis, minute ventilation (VE), heart rate (HR) and oxygen consumption (VO2) were measured in 10 elite male kayak paddlers (age = 25 +/- 6.5 yrs, height = 183.6 +/- 4.4 cm, mass = 83.9 +/- 6.1 kg) during steady-state exercise at a standardized velocity in conditions of "wash riding" (WR) and "non-wash riding" (NWR). The data were collected in field conditions using a portable telemetric metabolic system (Cosmed K2). Statistical analysis of the mean values for VE, VO2 and HR was performed using the Hotelling's T2 statistic and revealed significant (p < 0.05) differences between the WR and NWR trials for all three dependent variables. Mean values for VE (l/min) were WR = 113 +/- 16.5, NWR = 126.3 +/- 15.7; for VO2 (l/min) were WR = 3.22 +/- 0.32, NWR = 3.63 +/- 0.3; and for HR (bpm) were WR = 167 +/- 9.9, NWR = 174 +/- 8.0. It was concluded that wash riding during kayak paddling confers substantial metabolic savings at the speeds tested. This has implications for the design of training programs and competitive strategies for flatwater distance kayak racing.

Abstract

Seventy-one athletes with 74 stress injuries to the femur were studied using a case-controlled design. Forty-three were females (26.6 yrs) and 28 were males (31.2 yrs). Each patient had exercise-induced pain in the hip, groin or thigh and a Tec-99m-MDP bone scan showing focal uptake of radionuclide in the femur. Running was the most common activity at the time of injury (89.2%) followed by triathlon (4.6%) and aerobic dance (4.6%). Thirty per cent of the runners had increased their training duration immediately prior to their first symptom. Anterior thigh pain was the most frequent site of exercise-induced pain (45.9%) followed by hip pain (27%) and groin pain (8.1%). During the clinical examination, when asked to hop on the affected limb, 70.3% of the patients had pain reproduced in the hip, groin or anterior thigh. There were 39 cases (53%) involving focal uptake of radionuclide in the femoral shaft, 15 (20%) in the lesser trochanter, 11 (15%) in the intertrochanteric region between the femoral neck and the greater trochanter, 8 (11%) in the femoral neck and 1 (1%) in the greater trochanter. Two patients suffered displaced fractures, one at the femoral neck and the other in the shaft of the femur. Neither patient had previously sought medical attention for their leg pain. Of 46 plain radiographs taken, only 11 (24%) were abnormal. The mean time to diagnosis and recovery were 6.6 and 10.4 weeks respectively. Substitution of cycling and water exercise for running were the most common therapeutic interventions.

Abstract

Injuries and diseases of the musculoskeletal system account for more than 20% of patient visits to primary care and emergency medical practitioners. However, less than 3% of the pre-clinical medical school curriculum is devoted to teaching all aspects of musculoskeletal disease, and only 12% of medical schools require mandatory training in musculoskeletal medicine during the clinical years of undergraduate medical education in Canada. Available elective training in musculoskeletal injuries and diseases is commonly taught by hospital-affiliated physicians and surgeons, with the result that this teaching case load is typically skewed towards serious and/or surgical problems. The disparity between the clinical competence required for musculoskeletal problems in clinical practice and the content and format of medical education has not yet been addressed by changes in medical school curricula. One of the reasons for this is that the available morbidity statistics, which provide data regarding the frequency of specific musculoskeletal diagnoses, are based on diagnostic codes which are imprecise and incomplete. This prohibits the accurate selection of course content in this area, which is among the first steps in the development of a curriculum.

Abstract

It has long been appreciated that rates of ATP utilization and production need to be extremely closely balanced. To put it in molecular rather than molar terms, in human muscle engaged in a 15-min work protocol, approximately 3.3 x 10(20) ATP/g are used and resynthesized at approximately 100 times the resting cycling rates before fatigue, during which time only a 20-25% decrease in the ATP pool is sustained. Analysis of how such remarkable regulatory precision is achieved suggests that in resting muscle myosin behaves as a latent catalyst whose full catalytic potential 1) is realized with the arrival of an activator signal (Ca2+) and 2) is tempered with reaction products; such proactive control, initiated at ATP utilization, sets the required flux through ATP-producing pathways. For any given enzyme step in ATP-producing pathways, reaction velocity (v) becomes the independent parameter, with substrate concentration ([S], the dependent parameter) being adjusted accordingly. Because the dynamic range for muscles (change from resting to maximum ATP turnover rates) can exceed 100-fold, in many studies of working muscle the percent change in ATP turnover rate exceeds (sometimes by very large margins) the percent change in [S]. These observations are not easily explained by current metabolic regulation models but are consistent with pathway enzymes behaving as latent catalysts in resting muscle. In this view, the unmasking of such latent catalytic potential is the main explanation for how large changes in v can be achieved with modest (sometimes immeasurable) changes in [S].(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract

This study reports on the development of a model for studying skeletal muscle metabolism in humans using NMR spectroscopy. Graded exercise was simulated using electrical stimulation in 10 healthy, fit subjects (mean VO2max = 53 +/- 4 ml.kg-1.min-1). The effects of varying the stimulation parameters, namely, the stimulation frequency, the stimulation intensity, and the duty cycle, as well as the spectral interrogation volume, were compared using data acquired from the rectus femoris muscle. With stimulation, the inorganic phosphate to phosphocreatine concentration ratio ([P(i)]/[PCr]) and the intracellular pH both follow curvilinear relationships over the stimulation frequencies from 3 to 30 Hz, with the magnitude of the observed change related closely to stimulation intensity and duty cycle. Oxidative phosphorylation predominates at stimulation frequencies below 12 Hz, while anaerobic metabolism increases sharply above 12 Hz. Our findings show clearly the interdependence of the effects of the various stimulation parameters and emphasize the care that must be exercised in interpreting the physiological significance of the biochemical data obtained from electrical stimulation models used to study skeletal muscle metabolism.

Abstract

Overall lung volumes, regional residual volume to total lung capacity ratio (RVr/TLCr), regional ventilation (V/V) and perfusion (Q/V) were measured at 670 m in six Quechua Indians on days 2 and 37 after leaving their high-altitude homes (3500-4500 m). On day 2 the lung volumes averaged between 124 and 137% of those predicted for low-altitude residents (LAR) and there were no significant changes on day 37. Although overall RV/TLC was not different from the predicted value for LAR, RVr/TLCr on day 2 was higher at the top and lower at the bottom of the lungs compared to LAR. Regional Q/V and V/V were not different from LAR on day 2, or on day 37. However, the ratio of Q/V at the bottom to Q/V at the top was 2.36 on day 2 and 2.84 on day 37 (P less than 0.05). On day 2 hemoglobin- and volume-corrected diffusing capacity was 145% of the value predicted for LAR and this fell to 135% predicted on day 37 (P less than 0.05). Natives of high altitude reportedly have more alveoli that LAR and this could explain the greater vital capacity toward the bottom of the lung if the alveolar proliferation is concentrated there. This might also lower pulmonary vascular resistance at the bottom which would explain the normal Q/V distribution, even though pulmonary artery pressure may be increased.

Abstract

Six male Quechua Indians (34.0 +/- 1.1 yr, 159.5 +/- 2.1 cm, 60.5 +/- 1.6 kg), life-long residents of La Raya, Peru (4,350-m altitude with an average barometric pressure of 460 Torr), were studied using noninvasive methods to determine the structural and functional changes in the cardiovascular system in response to a 6-wk deacclimation period at sea level. Cardiac output, stroke volume, and left ventricular ejection fractions were determined using radionuclide angiographic techniques at rest and during exercise on a cycle ergometer at 40, 60, and 90% of a previously determined maximal O2 consumption. Subjects at rest were subjected to two-dimensional and M-mode echocardiograms and a standard 12-lead electrocardiogram. Hemoglobin and hematocrit were measured on arrival at sea level by use of a Coulter Stacker S+ analyzer. After a 6-wk deacclimation period, all variables were remeasured using the identical methodology. Hemoglobin values decreased significantly over the deacclimation period (15.7 +/- 1.1 to 13.5 +/- 1.2 g/dl; P less than 0.01). The results indicate that the removal of these high-altitude-adapted natives from 4,300 m to sea level for 6 wk results in only minor changes to the cardiac structure and function as measured by these noninvasive techniques.

Abstract

Two metabolic features of altitude-adapted humans are the maximal O2 consumption (VO2max) paradox (higher work rates following acclimatization without increases in VO2max) and the lactate paradox (progressive reductions in muscle and blood lactate with exercise at increasing altitude). To assess underlying mechanisms, we studied six Andean Quechua Indians in La Raya, Peru (4,200 m) and at low altitude (less than 700 m) immediately upon arrival in Canada. The experimental strategy compared whole-body performance tests and single (calf) muscle work capacities in the Andeans with those in groups of sedentary, power-trained, and endurance-trained lowlanders. We used 31P nuclear magnetic resonance spectroscopy to monitor noninvasively changes in concentrations of phosphocreatine [( PCr]), [Pi], [ATP], [PCr]/[PCr] + creatine ([Cr]), [Pi]/[PCr] + [Cr], and pH in the gastrocnemius muscle of subjects exercising to fatigue. Our results indicate that the Andeans 1) are phenotypically unique with respect to measures of anaerobic and aerobic work capacity, 2) despite significantly lower anaerobic capacities, are capable of calf muscle work rates equal to those of highly trained power- and endurance-trained athletes, and 3) compared with endurance-trained athletes with significantly higher VO2max values and power-trained athletes with similar VO2max values, display, respectively, similar and reduced perturbation of all parameters related to the phosphorylation potential and to measurements of [Pi], [PCr], [ATP], and muscle pH derivable from nuclear magnetic resonance. Because the lactate paradox may be explained on the basis of tighter ATP demand-supplying coupling, we postulate that a similar mechanism may explain 1) the high calf muscle work capacities in the Andeans relative to measures of whole-body work capacity, 2) the VO2max paradox, and 3) anecdotal reports of exceptional work capacities in indigenous altitude natives.

Abstract

Maximum O2 and CO2 fluxes during exercise were less perturbed by hypoxia in Quechua natives from the Andes than in lowlanders. In exploring how this was achieved, we found that, for a given work rate, Quechua highlanders at 4,200 m accumulated substantially less lactate than lowlanders at sea level normoxia (approximately 5-7 vs. 10-14 mM) despite hypobaric hypoxia. This phenomenon, known as the lactate paradox, was entirely refractory to normoxia-hypoxia transitions. In lowlanders, the lactate paradox is an acclimation; however, in Quechuas, the lactate paradox is an expression of metabolic organization that did not deacclimate, at least over the 6-wk period of our study. Thus it was concluded that this metabolic organization is a developmentally or genetically fixed characteristic selected because of the efficiency advantage of aerobic metabolism (high ATP yield per mol of substrate metabolized) compared with anaerobic glycolysis. Measurements of respiratory quotient indicated preferential use of carbohydrate as fuel for muscle work, which is also advantageous in hypoxia because it maximizes the yield of ATP per mol of O2 consumed. Finally, minimizing the cost of muscle work was also reflected in energetic efficiency as classically defined (power output per metabolic power input); this was evident at all work rates but was most pronounced at submaximal work rates (efficiency approximately 1.5 times higher than in lowlander athletes). Because plots of power output vs. metabolic power input did not extrapolate to the origin, it was concluded 1) that exercise in both groups sustained a significant ATP expenditure not convertible to mechanical work but 2) that this expenditure was downregulated in Andean natives by thus far unexplained mechanisms.

Abstract

In order to compare the clinical presentation of overuse injuries in older and younger athletes, retrospective patient chart data were obtained from cases which had been referred to an outpatient sports medicine clinic over a 5-yr period. A total of 1,407 cases were studied comprising two populations separated by significantly (P less than 0.001) different ages: 685 "old" (mean age = 56.9 +/- 6.1 yr) and 722 "young" (mean age = 30.4 +/- 8.1 yr). Although the two subpopulations demonstrated modest differences in sport activity at the time of injury, specific diagnoses, and anatomic location of injury, many similarities existed between the groups. Running, fitness classes, and field sports were more commonly associated with injury in the younger group, while racquet sports, walking, and low intensity sports were more commonly associated with injury in the older group. The frequency of tendinitis was similar in both age groups, while metatarsalgia, plantar fasciitis, and meniscal injury were more common in the older population, and patellofemoral pain syndrome (PFPS) and stress fracture/periostitis were more common in the younger population. Anatomically, injury sites in the foot were more frequent in the older group, while injury sites in the knee were more frequent in the younger group. In the older population, the prevalence of osteoarthritis was 2.5 times higher than the frequency of osteoarthritis as the source of activity-related pain. In the older group, 85% of the diagnoses were overuse injuries known to respond to conservative treatment, 14.4% of the cases required consultative referral, and only 4.1% required surgery.

Abstract

Seven healthy endurance-trained [maximal O2 uptake (VO2max) = 57.1 +/- 4.1 ml.kg-1.min-1)] female volunteers (mean age 24.4 +/- 3.6 yr) served as subjects in an experiment measuring arterial blood gases, acid-base status, and lactate changes while breath holding (BH) during intense intermittent exercise. By the use of a counterbalance design, each subject repeated five intervals of a 15-s on:30-s off treadmill run at 125% VO2max while BH and while breathing freely (NBH). Arterial blood for pH, PO2, PCO2, O2 saturation (SO2) HCO3, and lactate was sampled from a radial arterial catheter at the end of each work and rest interval and throughout recovery, and the results were analyzed using repeated-measures analysis of variance. Significant reductions in pHa (delta mean = 0.07, P less than 0.01), arterial PO2 (delta mean = 24.2 Torr, P less than 0.01), and O2 saturation (delta mean = 4.6%, P less than 0.01) and elevations in arterial PCO2 (delta mean = 8.2 Torr, P less than 0.01) and arterial HCO3 (delta mean = 1.3 meq/l, P = 0.05) were found at the end of each exercise interval in the BH condition. All of the observed changes in arterial blood gases and acid-base status induced by BH were reversed during the rest intervals. During recovery, significantly (P less than 0.025) greater levels of arterial lactate were found in the BH condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract

Abnormalities of lower-leg alignment may lead to a number of skiing problems. Tibia vara may cause difficulties in turning and riding a flat ski unless the boot cuff is properly adjusted to the lower leg. Varus deformities in the foot may lead to boot-fitting difficulties, foot and knee pain, and the inability to edge a ski turn properly. Compensation for these problems with an appropriately posted, corrective, orthotic device may allow skiing participation with greater comfort and better performance.

Abstract

Iron status was surveyed amongst 92 Winter Olympic sport athletes from Nordic and Alpine skiing, figure and speed skating and ice hockey. Haemoglobin and serum ferritin values were obtained by physicians as part of a monitoring programme, since iron deficiency would have an adverse effect on maximal performance. Four (7%) of 56 men were anaemic (Hb less than 14.0 g dl-1) and three (8%) of 36 women had haemoglobin values less than 12.0 g dl-1. Nine men (16%) and 14 women (39%) had prelatent iron deficiency (serum ferritin less than 30 ng ml-1). Ice hockey had the lowest while Nordic skiing had the highest incidence of sub-optimal iron status. A total of 50% of Nordic women skiers had prelatent iron deficiency and 7% were anaemic. An equal percentage of women speed skaters were low in serum ferritin as well. Only one of 20 male ice hockey players was low in serum ferritin. These results suggest there would be value in instituting screening procedures for iron status in Winter Olympic Sports.

Abstract

We analyzed cases of 320 athletes with bone scan-positive stress fractures (M = 145, F = 175) seen over 3.5 years and assessed the results of conservative management. The most common bone injured was the tibia (49.1%), followed by the tarsals (25.3%), metatarsals (8.8%), femur (7.2%), fibula (6.6%), pelvis (1.6%), sesamoids (0.9%), and spine (0.6%). Stress fractures were bilateral in 16.6% of cases. A significant age difference among the sites was found, with femoral and tarsal stress fractures occurring in the oldest, and fibular and tibial stress fractures in the youngest. Running was the most common sport at the time of injury but there was no significant difference in weekly running mileage and affected sites. A history of trauma was significantly more common in the tarsal bones. The average time to diagnosis was 13.4 weeks (range, 1 to 78) and the average time to recovery was 12.8 weeks (range, 2 to 96). Tarsal stress fractures took the longest time to diagnose and recover. Varus alignment was found frequently, but there was no significant difference among the fracture sites, and varus alignment did not affect time to diagnosis or recovery. Radiographs were taken in 43.4% of cases at the time of presentation but were abnormal in only 9.8%. A group of bone scan-positive stress fractures of the tibia, fibula, and metatarsals (N = 206) was compared to a group of clinically diagnosed stress fractures of the same bone groups (N = 180), and no significant differences were found. Patterns of stress fractures in athletes are different from those found in military recruits. Using bone scan for diagnosis indicates that tarsal stress fractures are much more common than previously realized. Time to diagnosis and recovery is site-dependent. Technetium99 bone scan is the single most useful diagnostic aid. Conservative treatment of stress fractures in athletes is satisfactory in the majority of cases.

Abstract

Stress fractures are commonly found in athletes attending sports medicine clinics for diagnosis of lower limb pain. Plain radiographs are less reliable than the 99mTc bone scan for diagnosing stress fractures because of their low sensitivity. While the heightened sensitivity of the bone scan is advantageous as a diagnostic aid, the uptake of 99mTc at non-painful sites occurs frequently in the athlete. Although the clinical significance has not been determined, asymptomatic uptake may indicate bone remodelling as part of a continuum of adaptation to physical stress. It is not known whether athletes who have uptake of 99mTc in asymptomatic areas represent a separate population from those who do not. This study retrospectively reviewed the medical charts and bone scan reports of 320 athletes diagnosed as having stress fractures, to determine the frequency of asymptomatic focal uptake at sites other than the site of pain. This group was compared with the group who had no asymptomatic uptake on a number of demographic variables and physical findings. Asymptomatic focal uptake was found in 37.5% of athletes with the average number of sites being 1.8 per person. No significant differences between groups with focal asymptomatic uptake and groups with no asymptomatic uptake were found when compared for age, height, weight, mileage in runners, times to diagnosis and recovery, frequency of tenderness, swelling, trauma history, varus alignment, and x-ray abnormalities. It is concluded that asymptomatic uptake of 99mTc occurs frequently in athletes with stress fractures and there are no significant clinical differences between the group with asymptomatic uptake and the group without. It is suggested that symptomatic uptake of 99mTc represents the remodelling response of bone to physical stress.